[Cube] Firewire Hang Ups

[S.L.]

I have some recurring problems with my Firewire ports and external CD and DVD drives.  The external drives are both Lacie and both run by Toast 6x.  When I added the CD drive, the ports shut down (system profiler did not even recognize they were there).  I got some tech advice, used the reset buttons and after several tries the external drive worked just fine.  

Later I added the DVD drive, daisy chained through the CD drive, but the ports shut down again.  After using the resets a bunch of times, and reinstalling Toast 6x, I can now use the DVD when it is plugged directly into the Cube, but not the CD!

I'm no tech guru, but I thought Firewire was pretty simple plug-and-go technology.  What is the secret to using external firewire drives with a Cube OSX 10.3?  Is there a weakness in the firewire hardware of the Cube?

Thanks for any feedback, Cubists.